Analytical Facility Core consist of three units the Analytical Chemistry, Exposure Assessment, and Aerosol Science Facility Core (Analytical Facility Core) provides exposure assessment services to Center investigators for proposal preparation and the conduct of environmental research studies. Several existing laboratories are joined together to form this Core, all located at UCLA. In addition, the UCLA program has recently been designated an SCPCS, and the NIEHS Analytical Facility Core has been augmented and complemented by the additional resources supplied by that major grant, forming a new primary analytical service lab called the Particulate Matter Center Analytical Laboratory (PMCAL). Objectives of the Core are: to provide trace analyses of contaminants in environmental samples; provide consultation and expertise on air sampling and analysis; provide consultation and planning for exposure assessment; provide exposure assessment assistance to Center investigators; encourage collaborative development of new methods and instruments; and serve as a referral link to the Exposure Assessment Research Core. The Analytical Chemistry Unit uses a variety of sensitive methods to quantify trace and ultra-trace levels of organic and inorganic chemicals and toxic compounds present in environmental samples. The Exposure Assessment Unit provides the means to conduct field measurements of environmental contaminants through direct readout instruments and field sampling. The Aerosol Science unit provides expertise in the area of aerosol properties and measurement. This unit is comprised of two laboratories (the Particle Instrumentation Unit (PIU) and the Aerosol Research Laboratories) which together provide instrumentation for sampling and measurement of airborne particles and particle size distributions. Dr. Antonio Miguel directs the Analytical Chemistry Unit, while the other two components are under the direction of Dr. Hinds. These Co-Directors are responsible for planning and coordination of all Analytical Facility Core operations. This includes priority setting, defining long-term equipment needs, ensuring appropriate QA/QC, interacting with research Cores, establishing instrument priorities between the NIEHS and EPA Centers, establishing training programs for technical staff, and other managerial tasks.